Alkoxyphenylalkyl-alkyl amines



Patented Jan. 24, 1950 ALKOXYlHENYLALKYL-ALKYL AMIN ES Robert Biedermann, Basel, Switzerland, assignor to J. R. Geigy A.-G., Basel, Switzerland, a Swiss No Drawing. Application May 7,1946, Serial No. 667,998. In Switzerland May 8, 1945 1 It has been found that therapeutically valuable compounds which are araliphatic amines of the general formula ArCH;CH-OH-NHR;

wherein I Ar means an unsubstituted or substituted aromatic radical, such as a phenyl, naphthyl, tetrahydronaphthyl, halogenophenyl, hydroxyphenyl, alkoxyphenyl, benzyloxyphenyl' radical and the like or homologous radicals,

R1 and R2 each mean an alkyl radical and Re means hydrogen or an alkyl radical,

will be obtained by converting ketones of the general formula Ar-CH CH-C=O V l I wherein Ar, R1 andRz have the above defined meanings, in a conventional manner into the corresponding amines and, if necessary, transinto the corresponding primary or secondary amines can be effected according to the most various known methods. Secondary amines may preferably;be produced by treating the ketones with reducing agents, like amalgamated aluminium or catalytically activated hydrogen, in the presence of the amines to be introduced. When working according to the catalytic hydrogenation method in the presence of ammonia primary amines may be made. The Leuckarts method can be used for the production of primary and secondary amines. According to this method the above defined ketones are condensed with formamide or with the formyl compounds of monoalkylamines and the resulting formyl compounds of the amines saponified to give the free amines; Furthermore, the ketones can be reduced to the secondary alcohols, thelatter be- 4 Claims. (Cl. 260-5703) ing then esterified by means of a hydrohalogenic t from the oximes or hydrazones of the ketones by .the above defined formula may also be obtained reducing the latter. Finally there may be mentioned that unsaturated ketones can be converted into the corresponding amines according to any one of the above described methods of hydrogenating amination, while simultaneously saturating the double bond.

Secondary amines may also be obtained by I alkylation of the corresponding primary amines, as has already been mentioned above. For such substitution of the amino group the known methods may be used; the most convenient method is that consisting in the interaction with hydrohalogenic esters or with sulfuric esters of alcohols or the interaction with aldehydes or ketones with reduction and the like. If desired, substituents present in the aromatic radical can also be transformed or split off after the amination. As examples may be mentioned: the conversion of the nitrogroup through the amino group into the hydroxy group, the splitting of alkoxy groups, saponification of acyloxy groupings to hydroxy groups and so on. If halogen atoms linked to an aromatic radical are present in the starting materials, the same can be replaced simultaneously with other operations, for instance with the reduction of Schiiis bases present as intermediate products, or also in a single operation by means of hydrogen.

The ketones'used as starting materialsas far as the same are unknown-can be prepared for instance byxaralkylation of ketones containing replaceable hydrogen at an a-carbon atom.

The invention will now be illustrated by the following examples without being limited thereto; the parts are by weight.

7 EXAMPLE 1 '15 parts of 1-(4'-methoXy'phenyl)-2-methylpentanone-('3) are dissolved in parts or" 94% alcohol and, after addition of 10 parts of an aqueous 41% monomethylamine solution, treated at 50-60" C., With 5 parts of aluminium amalgam. When the reduction has been completed, the aluminium hydroxide is filtered off, thorough Washing with alcohol carried off, the alcohol distilled off and the resulting secondary amine dissolved in dilute hydrochloric acid.- This solution is freed from the non-basic ingredients by means of ether and the base made free by means of caustic soda lye. The base isthen extracted with ether, the solution dried over anhydrous Glaubers salt, the ether distilled off and the free base, the l-(4- methoxyphenyl) 2 methyl-3-N-methylaminopentane, distilled in vacuo at 0.5 mm. pressure and at 102 C.

When starting from 1- (3:4-dimethoxyphenyl) 2-methyl-pentanone-(3) or from 1-(3:4-methylenedihydroxyphenyl) 2 methyl pentanone- (3) and methy1amine, the corresponding amines,

EXAMPLE 2 partsof l-(4-methoxyphe'nyl)-2 methylpeiita'n'One-(S) are heated for 8 hours to 165-170 C. with parts offo'rr'namide. Then the'm'aterial is allowed to cool and the "resulting 'foriz'iyl compound'is subjected to hydrolysis by heating the same under reflux for 3 hours with 100 parts of concentrated hydrochloric acid. A fte'rcomplete hydrolysis it is allowed to cool, diluted with small quantities of water and the base made free by means of a concentrated'solu- 4 phenyl)-2-methyl-pentanone-(3)V by means of sodium 'am'alg'a'm'in gIa'cialace'ticv acid; The resulting primary amine can be converted into the monomethyl amine derivative by means of formaldehyde and of a reducing agent, like for instance aluminumamalgam.

EXAMPLE 3 20' parts of 1-(S bromo-4-methoxyphenyl) -2 methylpentanone-(3) are dissolved in 140 parts of-9 l% alcohol"and-,-after addition of 10 parts of aqueous %nionoethylamine solution, treated at 60 C. with 7 parts of aluminum amalgam.

'Then working up continues in the manner described in Example 1. On reduction the bromine atom is"replacedby-hydrogen. W'l1'en u'singyinstead of the *bromin'ated derivative; the analogous chlorine compound, it will be necessary to wdrkat a higher temperature, as the chlorine is split off only at -100 0.

The so-obtained 1 (4 methoxyphenyl) 2 methyl-3-N-ethylaminopentane distils at 90 0., when using a pressure of 0.03 mm. 7

When working in the manner described either in "any" one of theabo've examples or in- Example 4, a large "number "of similarcompoundsmay be made; some of which areenumerated"in thefollowing table:

Substance Table I M P.0i the trge sg hydro" chloride 1- (4eth0'xyphen yl)2methyl3-Nme thylaminopentane 1- (4m et hoxyphcnyD-2-met hyl-3-N-iso propylaminopentane l- (4hydr6xyphe11yl)2m et hyl-3-N-ethylam inopentana. 1- (4-hydro xyphenyD-2-m et hyl-3-N-bu tylaminopentane tion-of sodiumhydroxide. The baseis extracted with'ether, the ether distilled off and'the residue dissolved'in dilute hydrochloric acid. After extraction'with ether the base-is again made free by means of caustic sodalye andextracted with ether, the ethereal solution being dried with anhydrous Glaubers salt. The solvent is subsequently distilled oiT and the base fractionated, The 1-(4'-methoxyphenyl) -2-methyl 3 aminopentane distils at 90 C. under a pressure of (3.06 mm. The latter compound can also be produced from 1- (4-methoxyphenyl) -2-methylpentene-l one-(3) by simultaneous amination and hydrogenation in the presence of platinum oxide or also by reduction of the oxime of the l- (4'-methoxy- EXAMPLE 4 20 parts of l (2 methoxyphenyl) Z-methylpentanone- (3) and- 8'pa'rts of ethylamine are-dissolved in60 par-ts of absolute benzene'and hydrogenated at 50 C.-with=0-.5 part ofplatinum oxide until the calculated: quantity I of hydrogen has been taken'u-p; Afterfiltration the base is-isolated as described in Example 1 anddistilled.

The 1--(2-:methoXyphenyl-). --2 methyl-3-N- ethyla'minopentane thus obtained distils at 10 When working in accordance with the methods described'in th'e above examples the 'follewiri'g 60 further compounds canbe pro'd'uced: v

Substance Table II I v M; P. of the I BVP. ofthe 1 free base hydro" l chloride l-(2-methoxy-5-methylphcnyD-2-methyl-3-N-ethylaminopentane1 l-(2-methoxypheny1)-2-methyl-3;aminopentane c EXAMPLES 20 parts of 1 (2':3' dimethoxy 5' bromophenyl)-2-methyl-pentanone-(3) are dissolved in 150 parts of 94% alcohol and treated at 60-70" C., in the presence of parts of an aqueous 41% methylamine solution, with 8 parts of aluminium amalgam. After completion of the reaction the aluminium hydroxide is filtered off and the base worked up as described in Example 1. Also in this case the bromine atom is replaced by hydrogen.

The 1- (2:3'-dimethoxyphenyl) 2 methyl 3- N-methylaminopentane distils at 107 C. under a pressure of 0.03 mm.

The following compounds may be obtained in a similar way: 1 (2:3' dimethoxyp'henyl) 2 methyl-3-N-ethylaminopentane B. P.o.o4. 113 C., 1- (2' 3'- dimethoxy-5- chlorophenyl) -2-methyl- 3-N-methylaminopentane B. P4107 126 C..

mide. After cooling the resulting formyl compound is subjected to hydrolysis by heating it under reflux for-3 hours with 100 parts ofconcentrated hydrochloric acid. When cold, the'mixture is diluted with water, made alkaline with a concentrated sodium hydroxide solution and the base is extracted with ether. After having expelled the solvent the residue is dissolved in dilute hydrochloric acid, the resulting solution again extracted with ether, the base made free by means of caustic soda lye, the base extracted with ether and the ethereal solution dried with anhydrous Glaubers salt. The ether is subsequently distilled off and the base fractionated. The l-(4-methylphenyl)-2-methyl-3 N methylaminopentane distils at 125 C. under a pressure of 11 mm.

According to the above method the following compounds may be produced:

Table III B. P. of the free Substance base 1-pheny1-2-methyl-3-N-ethylaminopentane 13. P40 120 C. l-2-methylphenyl)-2-methyl-3-N-methyl-aminopentane- B. P. 133 C. 1- a-naphthyD-Z-methyl-S-N-iso ropyl ammopentane B. PM! 112 C. 1-[a-(2'-methylnaphthy1) -2-met yl-3-aminoplentane B. P. 117 C. 1- a-(2'-methyluaphthyl) -2-metbyl-3-N-met ylaminopentane B. P 116 C. 1- a-(2-methylnaphthyl) -2-methyl-3-N-ethylaminopentane B. P.o.1 122 C. 1- a-(4-methylnaphthyl) -?-methyl-3-N-methylaminopentane-- B. P.o.1 122 C. 1- a-(4-methylnapl1thyl) -2-methy1-3-N -ethy1aminopentane B. P. 124 C. 1-(2-methylphenyl)-2-methyl-3-N-ethylaminopentane B. P. 135 C. 1-(3-methylphenyl)-2-methyl-3-N-methylaminopentane B. P. 02 85 C. 1-(3'-methylphenyl)-2-methyl-3-N-ethyl an iuopentane B. P40 125 C. 1-(4'-methylphenyl)-2-methyI-S-N-ethylammopentane B. B 1125" C. 1-(3'a4'-dimethylphenyl)-2-methyl-3-N-methylaminopentane B. P." 145 C. l-(3:4'-dimethy1phenyl)-2-methyl-3-N-ethylaminopentane B. P." 145 C. 1-22:4'-dimethylphenyl)-2-me1;hyl-3-N-ethylaminopentane B. P40 148 C. l- 2:4'-d1methylphenyl)-2-methy1-3-N-methylaminopentane- B. P40 144 C. l-(fl-tetrahydronaphythyl)-2-methyL3-N-methylaminopentane-- B. P 102 C. l-(B-tetrahydronaphthyl)-2-methyl-3-N-ethylaminopentane B. P-o.0l 108 C. l-EE-tetrahydronaphythyl)2methyl-ii-N-isopropylaminopentane B. P.a.oi 107 C. 1- wnaphthyl)-?-methyl-3-aminopentane B. PM; 111 C. l- (a-naphthyl)-2-methylB-N-methyla niuopentane B. Pam 115 C, l-(a-na hthyl)-2-methyI-B-N-ethylammopentane B. P.n.os 117 C. 1-(wnaphthyl)-2-ethyl-3-am1nohexane B. P. m 116 C. 1-(a-naphthyl)-2-ethyl-3-N-methy1aminohexane. B. P-uma 122 C 1- (a-naphthyD-2-ethy1-3-N -ethylaminohexane B. P 126 C (2':3-dimethoxy-5-chlorophenyl) 2 methyl- 3-N-ethylaminopentane B. P.o.o3 123 C.

EXAMPLE 6 To a solution of 20 parts of l-(3'-bromo-4- methoxyphenyl) -2-ethyl-n-hexanone-(3) in 140 parts of 94% alcohol are added 10 parts of aqueous 41% methylamine, whereupon the mixture is treated with 7 parts of aluminum amalgam. When at 60-70 C. the whole aluminum amalgam has been brought to reaction, the aluminum hydroxide is filtered 011 and the resulting mixture worked up in the manner described in Example 1. Also in this case the bromine atom is reductively split off.

The 1- (4 -methoxyphenyl) -2-ethyl-3-N-methyl-aminohexane distils at 104 C. under a pressure of 0.07 mm.

By splitting the methoxy group by means of boiling hydrobromic acid there will be obtained 1-(4'-hydroxypheny1) -2-ethyl-3 methylaminohexane; the melting point of its hydrochloride lies at 200 C. In a similar manner may be obtained 1-(4' methoxyphenyl) 2 methyl-B-N- 'ethylaminohexane, B. P.o,o4 102 C.

EXAMPLE 7 19 parts of 1-(4'-methylphenyl)-2-methylpentanone-(3) are heated to 165-170 C. for 8 hours together with 24 parts of methyl forma- What I claim is: 1. An araliphatic amine of the formula 1 to 6 carbon atoms, and Y stands for an alkyl radical containing 1 to 4 carbon atoms.

2. An araliphatlc amine of the formula OCzHl 3. An araliphatic amine oi the formula CHaO-O-CHg-CH-CH-NH-CH;

4. An araliphatic amine of the formula.

ROBERT BIEDERMANN.

(References on following pate) 

1. AN ARALIPHATIC AMINE OF THE FORMULA 